An orchid species exists that has a 25-25 cm long flower spur (the comet orchid), and 19th century botanists were puzzled as to how it could be pollinated in the wild. Darwin speculated that an insect with a long proboscis would be found to exist and researchers soon discovered the Sphinx Moth. [0]

[0] https://en.wikipedia.org/wiki/Angraecum_sesquipedale#Reprodu...